1. Field of the Invention
The invention relates to a pointing device, and more particularly, to a pointing device which uses an image picture to generate pointing signals.
2. Description of the Prior Art
A pointing device such as a mouse is used for generating pointing signals to control movements of a cursor on a display device. A prior art mouse commonly comprises two or three buttons installed on its housing for inputting button signals. The scrolling of a window on the display device can be performed by moving a scroll square on the scroll bar to another position. This is done by moving the cursor to a scroll bar of the window first and then depressing one of the buttons on the mouse.
Please refer to FIG. 1 and FIG. 2. FIG. 1 is a perspective view of a prior art mouse 10. FIG. 2 is a functional block diagram of the mouse 10. The mouse 10 is electrically connected to a computer system 20, and the computer system 20 is electrically connected to a display device 22. The mouse 10 comprises a housing 12, two buttons 14 positioned on an upper side of the housing 12 for inputting button signals, and a roller ball (not shown) installed on a bottom side of the housing 12 for controlling movements of a cursor on the display device 22.
The computer system 20 comprises a memory 24 for storing programs and data, a processor 26 for executing the programs stored in the memory 24, a button control program 28 stored in the memory 24 for receiving and processing the button signals generated by the buttons 14, and a display control program 30 such as Microsoft Word stored in the memory 24 for controlling the scrolling of a window 32 displayed on the display device 22 according to the button signals.
Because scrolling the window 32 requires a user to move the cursor to a scroll bar of the window 32 first, and then input button signals from one of the buttons 14. It is extremely inconvenient for the user.
It is therefore a primary objective of the present invention to provide a pointing device to solve the above mentioned problem.
Briefly, in a preferred embodiment, the present invention provides a pointing device comprising:
a housing;
a line-shaped contact image sensor installed on an upper side of the housing for inputting a line-shaped image and generating a corresponding line image signal, each line image signal comprising a predetermined number of data bits; and
an image processing circuit installed in the housing and connected to the image sensor for receiving and processing the line image signal generated by the image sensor;
wherein a user can move an image picture across the image sensor in a direction perpendicular to the line direction of the image sensor to sequentially generate a series of line image signals, and the image processing circuit saves the series of line image signals in a bit map format which contains the image of the image picture in it, and then the user can move the image picture across the image sensor to generate a first line image signal and a second line image signal, and the image processing circuit will convert the first and second line image signals into first and second coordinates according to the positions of the first and second line image signals within the bit map, and generate a pointing signal according to the difference between the first and second coordinates.
It is an advantage of the present invention that the pointing device comprises a line-shaped contact image sensor for inputting an image picture so that scrolling a window becomes an easy task.
These and other objects and the advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.